There are instances of erectile impotence in which the patient does not respond to more conventional therapy and the surgical implanting of a penile prosthesis may be the only practical means of remedying the impotency.
Several types of penile prostheses have been employed in the past. One type of penile prosthesis is a pair of rods of suitable stiffness which are surgically implanted into the corpus cavernosum of the penis. One disadvantage of some of the rod-type implants is the permanent stiffness of the rod which can be a source of physical pain and/or embarrassment to the patient. The prostheses disclosed in U.S. Pat. Nos. 3,893,476 and 4,066,037 are representatives of the rod type prostheses.
Another type of penile prosthesis which is available is the inflatable prosthesis of U.S. Pat. No. 3,954,102. The patented prosthesis includes two fairly long inflatable and distensible tubes that are surgically implanted in the corpus cavernosum of the penis. Each of the two tubes is connected by tubing to a pressure bulb of inflating fluid which is implanted elsewhere in the body. Because of the volume required to inflate, distend, pressurize and rigidize the inflatable tubes, the pressure bulbs are relatively large.
Recently penile implants have been patented which are essentially cylinders which contain a hydraulic system comprising a pressure chamber, a reservoir and a pump for transferring fluid from the reservoir to the pressure chamber. The pump must be manually squeezed to transfer the fluid to the pressure chamber. Representative of such implants are those of U.S. Pat. Nos. 4,353,360, 4,267,829 and 4,383,525.
Although the previously patented prostheses are useful and valuable devices, there is a need for an improved penile prosthesis which is easier to operate and which does not require pumping for an erection.